Pen



FIG. 1 is a front perspective view of a pen showing my new design;

FIG. 2 is a left side elevational view thereof, the right side being a mirror image;

FIG. 3 is a front elevational view thereof;

FIG. 4 is an enlarged bottom plan view thereof; and,

FIG. 5 is an enlarged top plan view thereof.

The pen has a flat U-shaped panel on the front surface as shown from the front in FIG. 2 and from the side in FIG. 3. 

CLAIM The ornamental design for a pen, as shown and described. 